Order books for the new Audi A6 have opened, with the executive car priced from £69,900 in saloon form and £71,700 as an estate.

It is available solely as an electric car, taking the fight to the BMW i5 and Mercedes EQE with up to 543bhp and 463 miles of range.

Unlike its primary rivals, which run adjacent to the combustion-engined E-Class and 5 Series, Audi has opted to transition one of its most important models to solely electric power. In turn, the outgoing petrol and diesel A6 will adopt the A7 moniker – previously reserved for Audi’s luxury four-door coupé – for a new generation that will arrive next year.

Visually, the new A6 E-tron remains faithful to the concept of the same name that was shown three years ago. The addition of equipment required for production – larger air intakes, full-size headlights and ADAS sensors – has made for a lightly restyled front end, but the sleek, muscular proportions remain intact.

The saloon follows its high-riding stablemate, the Q6 E-tron, onto the new Premium Platform Electric (PPE) architecture, offering 800V electrics as well as a broad range of battery packs and powertrains.

The headline performance statistic is the range-topping Sportback’s officail more than 463 miles, which eclipses the official figures for the equivalent i5 (356 miles) and EQE (429 miles). The estate-bodied A6 E-tron Avant concedes 26 miles of range, owing to its less aerodynamic shape, pegging it at a claimed 437 miles.

A key component in achieving those figures is a new and more efficient 94.9kWh (usable capacity) battery, which has been designed specifically for the PPE platform and comprises 12 modules and 180 cells. Audi has also confirmed that a 10-module 79kWh unit will become available shortly after the new A6’s launch.

Both batteries use a new lithium ion nickel-manganesecobalt make-up that is said to enable a 30% improvement in cell density over with the packs in the Q8 E-tron and E-tron GT.

The A6 can be recharged at 11kW on a domestic AC supply through either of its charging ports – mounted on each of the car’s rear haunches – but the driver’s side port can also take DC at rates of up to 270kW. An upgrade to 22kW AC charging is planned for later in the car’s life cycle.

Two powertrains will be offered. Entry-level cars will be badged Performance and get a rear-mounted permanent magnet synchronous motor that puts out 362bhp for a 0-62mph time of 5.4sec.

The S6, priced from £97,500, will add an asynchronous motor on the front axle, giving it four-wheel drive and a combined output of 496bhp in normal operation. Using the launch control function temporarily boosts it to 543bhp, cutting its 0-62mph time to 3.9sec.

Top speed is 130mph in the Performance model and 149mph in the S6. Range is rated at 406 miles in saloon form, or 388 miles for the estate.

The RS6 will also be reborn as a pure EV, offering stronger performance than the existing 621bhp V8 model.

Dynamically, the new A6 is said to have been set up for “first-class” comfort, with the Performance model riding on traditional steel springs and the S6 getting adaptive air suspension.

Top-spec models actively adjust their ride height on the move to aid aerodynamic performance and range. They also lift when parked and unlocked to enable easier entry. Inside, the A6 mirrors the layout of the new A5 and the Q6, with a large OLED screen taking centre stage.

This is divided into an 11.9in instrument panel and a 14.5in infotainment touchscreen. A 10.9in passenger display is offered as an option. In cars equipped with the optional camera side ‘mirrors’, a pair of small displays bookends the dashboard.

UK deliveries of the A6 E-tron will begin next February.